Utility providers face the problem of satisfying consumer demand for electrical energy during peak and off-peak demand periods. Total electrical energy demand may vary significantly between the peak and off-peak demand periods. For example, energy demand typically peaks on a hot summer afternoon as a result of the widespread simultaneous operation of air conditioning systems. And energy demand may subsequently drop during the off-peak period of the late evening.
To accommodate very high peak demands, utility providers face options of investing in additional power generating capacity, buying power from other utilities having excess capacity, or using an electrical load management system to control the amount of electrical energy distributed over the electrical distribution network during peak energy demand periods by electrical load reductions. Such load reductions are commonly referred to in the industry as load shedding. Load shedding is usually the more cost effective alternative to investing in expensive additional power generating capacity. Devices that are used to produce additional power generating capacity are often referred to in the industry as “peakers.”
As of this writing, many utility providers have turned to load shedding as the most viable option to address very high peak demands instead of purchasing peakers. Load shedding usually comprises “direct load control” or demand response programs. Direct load control is a method where utility providers may interrupt the loads of their consumers during critical energy demand times.
In exchange for permitting this interruption during a direct load control event, the consumer generally receives direct payments from the utility provider. As one example of load shedding, a homeowner on a direct load control program may find his air conditioner periodically interrupted on hot summer days by a switch operated remotely by the utility provider. In exchange for permitting this remote operation of the switch, the homeowner usually receives a payment from the utility provider.
This load cycling by the utility provider for a load control program may reduce overall energy consumption when electricity demand is highest, thereby improving grid reliability and reducing energy costs for the utility provider. In addition to load shedding for addressing peak energy demands, utility providers have been increasing the use of alternate energy sources, such as solar power from photovoltaic cells and solar power for steam-generation. Other alternate energy sources include wind energy from windmill powered turbines as well as traditional alternate energy sources like hydroelectric energy from dams.
Because alternate energy sources like solar power and wind power may produce energy surplus on occasions due to their unpredictability, utility providers need ways to expend this additional energy efficiently and without risking a disruption in energy service by shutting down critical energy sources. For example, suppose that a utility provider has a solar power source, a wind power source, and a nuclear power source. When either the solar power source or wind power source generate a surplus amount of energy, the utility provider will likely not want to shut down or lower the production of the nuclear power source to offset this surplus in energy being produced by the solar power source or wind power source or both. The utility provider will not want to shut down or reduce energy production at the nuclear power plant in order to be ready for when a demand in energy may peak suddenly.
Accordingly, what is needed is a system and method that may overcome the problems associated with the excess energy production from alternate energy sources like solar power and wind power, especially when the excess energy is not needed immediately in an energy distribution system. Another need exists in the art for system that can overcome both the problems associated with excess energy production as well as the problems associated with peak demands for energy when extra energy is needed in an energy distribution system.